Although Goyer sidestepped "Justice League" questions Monday at the red-carpet premiere for "Man of Steel" in New York City, he did playfully fire a warning in Marvel's direction. "They’ve got a little kryptonite pellet embedded in my heart and if I say anything it will explode, but I would be a very rich man for all the times I was asked that question," he said. "It all depends on how the ['Man of Steel'] does. I would love to see a Justice League film, absolutely. Put the Avengers on notice.”

Perhaps a bigger question is what part Christopher Nolan will play in the next Superman film. The man who resurrected the studio's Batman franchise co-wrote the story for "Man of Steel" with Goyer and served as producer and mentor to Snyder, but Deadline contends his role in the follow-up won't be as "full-blown."

That Warner Bros. is moving faster than a speeding bullet to put a sequel into development shouldn't come as a surprise: While early reviews are a bit mixed, early tracking suggests the franchise reboot could gross somewhere between $85 million and $100 million in its opening weekend in the United States. Warner Bros. and Legendary Pictures are, of course, managing expectations -- it's what studios do -- saying publicly that "Man of Steel" can look forward to a domestic debut north of $75 million, but rivals push that figure up, up and away.

Fandango, which began offering "Man of Steel" tickets May 21, reported last week that the film is outpacing all previous summer 2013 releases. However, when it comes to actual box-office performance, Marvel's "Iron Man 3" has set a high bar, grossing $1.2 billion globally and $387 million domestically. Still, Variety indicates that Warner Bros. and Legendary executives a projecting (presumably privately) that, when all is said and done, "Man of Steel" could see a $300 million-plus North American haul.

"Man of Steel," which cost about $225 million to produce and another $150 million or more to market and release, stars Henry Cavill as Superman/Clark Kent, Amy Adams as Lois Lane, Michael Shannon as Zod, Kevin Costner as Jonathan Kent, Diane Lane as Martha Kent, Russell Crowe as Jor-El, Ayelet Zurer as Lara Lor-Van, Antje Traue as Faora, Laurence Fishburne as Perry White, Christopher Meloni as Colonel Hardy, Harry Lennix as General Swanwick, Michael Kelly as Steve Lombard and Richard Schiff as Dr. Emil Hamilton.